GUWAHATI, Nov 7 - Even as thousands of dams are being planned to be built on the rivers of Africa and Asia, dozens of large-scale hydropower projects in Europe and the United States (US) are being removed every year. This was stated by Matt McGrath, Environment correspondent of the BBC in a write-up titled ‘Large hydropower dams not sustainable in the developing world’ published on November 5, 2018 in the BBC News Science and Environment section. He was referring to a new study on the large-scale hydropower projects.

McGrath said that building of hydropower dams reached its zenith in Europe and the US in the 1960s and has been in the decline since then. More such dams are now being dismantled than installed. Hydropower now supplies around six per cent of electricity in the US. Dams are being removed at a rate of more than one a week on both sides of the Atlantic, said McGrath, referring to the above study.

Citing the paper prepared by the scientists, who were involved in the above study, and published in the journal ‘Proceedings of the National Academy of Sciences’, the BBC Correspondent said the governments were blindsided by the prospect of cheap electricity without taking into account the full environmental and social costs of these projects.

More than 90 per cent of the dams built since the 1930s were more expensive than anticipated. They have damaged river ecology, displaced millions of people and have contributed to climate change by releasing greenhouse gases from the decomposition of flooded lands and forests, McGrath said.

In the developing world, an estimated 3,700 dams, large and small, are now in various stages of development. The authors of the above paper say their big worry is that many of the bigger projects will do irreparable damage to the major rivers on which they are likely to be built.

The authors said that with huge pressure on countries to press ahead with renewable energy developments, a mix of energy sources including hydro is the most sustainable approach. “Large hydropower doesn’t have a future, that is our blunt conclusion,” Prof Emilio Moran of Michigan State University, also a lead author of the above paper, told McGrath.